feat: integrate real data into dashboard

- Created dashboard service with DB queries for users, economy, events
- Added client stats provider with 30s caching for Discord metrics
- Implemented /api/stats endpoint aggregating all dashboard data
- Created useDashboardStats React hook with auto-refresh
- Updated Dashboard.tsx to display real data with loading/error states
- Added comprehensive test coverage (11 tests passing)
- Replaced all mock values with live Discord and database metrics

web/src/hooks/use-dashboard-stats.ts

@@ -0,0 +1,78 @@
+import { useState, useEffect } from "react";
+
+interface DashboardStats {
+    guilds: {
+        count: number;
+    };
+    users: {
+        active: number;
+        total: number;
+    };
+    commands: {
+        total: number;
+    };
+    ping: {
+        avg: number;
+    };
+    economy: {
+        totalWealth: string;
+        avgLevel: number;
+        topStreak: number;
+    };
+    recentEvents: Array<{
+        type: 'success' | 'error' | 'info';
+        message: string;
+        timestamp: string;
+        icon?: string;
+    }>;
+    uptime: number;
+    lastCommandTimestamp: number | null;
+}
+
+interface UseDashboardStatsResult {
+    stats: DashboardStats | null;
+    loading: boolean;
+    error: string | null;
+}
+
+/**
+ * Custom hook to fetch and auto-refresh dashboard statistics
+ * Polls the API every 30 seconds
+ */
+export function useDashboardStats(): UseDashboardStatsResult {
+    const [stats, setStats] = useState<DashboardStats | null>(null);
+    const [loading, setLoading] = useState(true);
+    const [error, setError] = useState<string | null>(null);
+
+    const fetchStats = async () => {
+        try {
+            const response = await fetch("/api/stats");
+
+            if (!response.ok) {
+                throw new Error(`HTTP error! status: ${response.status}`);
+            }
+
+            const data = await response.json();
+            setStats(data);
+            setError(null);
+        } catch (err) {
+            console.error("Failed to fetch dashboard stats:", err);
+            setError(err instanceof Error ? err.message : "Failed to fetch stats");
+        } finally {
+            setLoading(false);
+        }
+    };
+
+    useEffect(() => {
+        // Initial fetch
+        fetchStats();
+
+        // Set up polling every 30 seconds
+        const interval = setInterval(fetchStats, 30000);
+
+        // Cleanup on unmount
+        return () => clearInterval(interval);
+    }, []);
+
+    return { stats, loading, error };
+}